1. Field of the Invention
The present invention relates to a method for improving the performance of a motor, and more particularly to a method for reducing the vibration of a motor having a carrier interface.
2. Description of the Prior Art
Generally, the motor having a carrier interface is used in the applications of a CD player, a DVD-ROM or a hard disk. As shown in FIG. 1(a) and FIG. 1(b), a conventional motor typically includes a motor 10 and a carrier interface 20. Among these, the carrier interface 20 is used to load a storage medium such as a CD (not shown). Besides, as shown in FIG. 1(b), the carrier interface 20 is connected to the stator of a motor 10 via a shaft 30. A head such as an optical head can access the data recorded in the storage medium rotated by the motor 10 and the shaft 30. The carrier interface 20 further includes a rough sheet 50 formed thereon, as indicated by the oblique line of FIG. 1(a). The rough sheet 50 further includes a rough surface to enhance a frictional force such that the storage medium positioned thereon can be fixed properly.
However, in the prior art, the verticality of the carrier interface 20 or the rough sheet 50 relative to the shaft 30, or the flatness of the rough sheet 50 is not satisfied. In this case, when the motor 10 is rotating, the relative distance from the storage medium to the head is not constant. As a result, the so-called vibration problem occurs and an access to the storage medium is thus affected. As the rotation speed of the motor is raised increasingly, the vibration problem is more serious.
In the prior art, the method for solving the vibration problem is shown in FIG. 1(c) and illustrated as follows. A motor having a carrier interface is positioned on the base 60 of an apparatus. A cap 70 is put on the carrier interface 20. Then, the carrier interface 20 is rotated. Meanwhile, a probe 80 is used to detect the height of the surface of the cap 70 such that the higher point and the lower point of the carrier interface 20 can be indirectly determined. Thereafter, based on the resulting topography of the carrier interface 20, the higher point of the cap 70 is pressed down so as to adjust the verticality of the carrier interface 20 relative to the shaft 30. The above-mentioned steps are repeated until the final topography is satisfied. However, the above-mentioned method is achieved manually. Besides, the carrier interface 20 still has the minimum height difference of at least 50 micrometer. Unfortunately, the pressing step in the above-mentioned method may damage the structure of the motor, and especially the shaft. If the undesirable vibration problem is not solved effectively, the high-level recording apparatus, such as DVD or high speed CD-ROM, maybe affected seriously, since they requires more accuracy in tolerance.
Accordingly, there has been a strongly felt need for providing a more effective solution for the vibration problem without damaging the structure of the shaft.
Therefore, the main object of the present invention is to provide a method for solving the aforementioned vibration problem.
It is a general object of the present invention to provide method for improving the performance of the motor.
First, a rotor assembly is provided. As known in the prior art, the rotor assembly includes a magnetic ring and a metal case. The rotor assembly further includes a shaft. One terminal of the shaft is coupled to a carrier interface, such as a turn table. The carrier interface further includes a rough sheet having a rough surface to enhance the frictional force such that object positioned thereon can be fixed properly.
Then, a polishing step is performed to polish the rough sheet. The carrier interface is rotated around the first rotation direction. For example, the stator is clamped and rotated by a suitable apparatus. Thereafter, the rough sheet is polished by a polisher, such as a grinder, rotating around the second rotation direction. Besides, during the polishing process, the polisher further moves along the direction perpendicular to the axis of the shaft. For example, the polisher moves from the outer periphery to the inner periphery of the rough sheet. As a result, the verticality between the surface of the rough sheet and the shaft can be increased significantly through the polishing step. The vibration problem is thus solved.
After the rough sheet is polished completely, the assembling step is performed. Via another terminal of the shaft, the rotor assembly is combined with a stator assembly so as to form a motor having a carrier interface. In this manner, the improved verticality between the carrier interface and the shaft is achieved. That is, the above-mentioned method provided by the present invention can prevent the vibration effectively.